The Chicago Pediatric AIDS Clinical Trials Unit (C-PACTU) plans to participate in the multi-center AIDS clinical trials proposed by the Coordinating and Operations Center (CORC). Our goal is to participate in protocols that are hypothesis-based and pathogenesis-oriented trials designed to 1) define the virologic and immunologic mechanisms of perinatal transmission and evaluate the potential of antiretrovirals and immunomodulators (including vaccines) to reduce such transmission. 2) expeditiously evaluate the effect of promising new antiretroviral combinations on viral load, immunologic markers and/or clinical outcome; 3) increase our understanding of HIV immunopathogenesis in children and adolescents and the role of immune-based and/or gene therapy; 4) prevent or manage opportunistic infections and investigate their effect on the progression of HIV infection; 5) facilitate enrollment, treatment, and compliance of HIV-infected adolescents; and 6) increase quality of life and long-term outcomes. We have special interest in phase I/II studies and plan to continue our participation in these (more difficult) protocols. In addition, we plan to increase participation of HIV-infected women who are being cared for at our unit in ACTG studies. The proposed four units of the C-PACTU are located in different parts of the city of Chicago. The wide-range catchment area of the C-PACTG and the linkages it has developed with many community-based agencies will allow us to reach effectively many of the children, adolescents and women known to be affected by the HIV epidemic in Chicago and the surrounding area. The unit is also engaged in international scientific exchange and research with a site in Capetown, South Africa.